Dyeing poly amide fibers



1 first r e293. it

Patented Jan. 17, 1967 minutes at a temperature of about 50 to 100, and preferably 60 to 85 C.

As polyamide fiber these of natural originabove all wool and silk, as well as synthetic polyamide fibers such as the various kinds of nylon, e.g. nylon 6, nylon 66 and nylon 11 (Ri-lsan), are suitable for the after-treatment according to the invention.

The polyamide fibersfare dyed by known methods in .a

, dyestuif solutionwhioh, in addition to the known dye- This invention relates to improvements in dyeing polyamide fibers as well as,as industrial product, the dyed polyamide fibers treated accordingto the'invention.

I Hitherto, wool and other polyamide fibers including nylon and the like synthetic polyamidefibers Whichhad been dyed with reactive dyestuffscontaining per molecule at least one substituent WlfliCh1Qan be split off as an anion during the dyeing and/or after-treatment of the dyed fibers had to be subjected to an after-treatment in an aqueous basic mediumof a pH of preferably about 7. 5

or higher which contains, for example, sodium hydroxide,

in the dyed goods, suffers from the drawback that the polyamide fibers can be injuredby the alkaline medium and particularly by a subsequent drying stepif the same. is carried out directly on the after-treatedfibers.

, Therefore, in the known dyeing methods the aftertreatment with an alkaline medium fol-lowed usually by a further treatment in an acid medium prior to final drying ofthedyedfibers. p

Another drawback of the after-treatment with alkaline agents such as ammonia or hexamethylenetetramine resides in the tendency of the alkaline bath to remove at least part of the still unreacted dyestuff from the fibers, whereby an exact control of the shade of the fixed dyeings is made very difficult.

It is, therefore, an object of the present invention to provide in a process of dyeing polyamide fibers with reactivedyestuffs of the type described, an aftertreatment of the dyed fibers for the purpose of fixing still unreacted residual dyestuif or the fibers, which after treatment does not injure the fibers, permits of dyeing the aftertreatment fibers directly without further intermediatetreatments, and allows for a more exact control in producing a desired shade.

These objects are attained by the treatment according to the invention, which comprises; as an aftertreatment in a process for dyeing polyamide fibers, after heating and thereby reacting these fibers in an acid dye-bath with a reactive d'yestuit which contains at least one mobile substituent capable of being split off as anion, and after substantial exhaustion of the dyebath,

(I) Adding to the dyebath still containing the fibers a condensation product of (a) A naphthalene sulfonic acid, in particular a monoto trisul'fonic acid, and preferably naphthalene-Z-monosulfonic acid, or a l,2,3,4-tetrahydronaphthalene sulfonic acid, 1

(b) From about 0.5 to 1.5, and preferably from 0.8 to 1.2 part'by weight,per part by weight of (a), of a compound of the formula HO-phenylene SOfphenylene-OH, preferably droxydip henylsulfone, and (c) From about 0.1 to 0.2, and preferably 0.1 part by weight, per part by weight of (a), of formaldehyde, in

aqueous, preferably about -soluti,on, and

issued April 5, 1935.

stuffs, can also contain the auxiliaries usual in wool dyeing, for example, s'alts such as sodium. sulphate or ammonium sulphate, and/ or dilute acids, e.g. acetic or formic acid and/ or wetting agents, e.g. condensation products of fatty'acids having at least 8 carbon atoms with lower alkanolamines such as are described in U.S. Patent 2,089,212. t After the dyestuif has been drawn onto the fibers and the dyebath is satisfactorily exhausted, the dyed goods are after-treated according to the,invention in the same bath as that in which they. weredyed, by adding thecondensation product, preferably in dissolved form,'alone or together with other additives usual in textile dyeing, and moreover, preferably incondition withan acid, especially acetic or formic acid or their water soluble salts, to the at least slightly cooled dyebath whichhas a pH of about 5 4 to 5.5, and preferably. 4,5 [05. Acetic acid is preferred. V t v The aforesaid condensation products which are suitable for use in the treatment according to the. invention are produced as describedin German Patent 611,671,

The content of these condensation products in the treatment liqupr. should be about 0.5 to 3 grams per liter.

The reactive dyestuffs which can .be used according to the invention can be of the most various classes of dyestuifs. Advantageously they are the nitro, a'zo, anthraquinone and phthalocyanine dyestuff classes which are distinguished by their stability. They contain water solubilizing, acid salt-forming groups, mainly sulphonic acid groups, also they may contain carboxyl groups or sulphamyl groups, .in the latter case, also acylated sulphamyl groups among others, e.g. disulphimide and carbonyl sulphimide groups. The advantages attainable according to the invention are particularly impressive if reactive dyestuffs usual for the fast dyeing of cellulose are used, which dyestuffs contain several sulfonic acid groups, for example, 2 to 4 per dyestuif molecule. Thus, the dyestuffs used according to the invention are, for example, nitrodiarylamino sulphonic acids, metal-free monoand poly-azo dyestuffs, heavy metal-containing, for example, chromium or cobalt containing, o,o'-dihydroxy, ohydroxy-o'-carboxy, and o-hydroxy-o' -amino monoazo and disazo dyestuffs, copper containing formazane dyestuffs, 1-amino-4-phenylamino-anthraquinone dyestuffs, copper phthalocyanines having substituted sulphamyl groups, all of which preferably contain at least two sulphonic acid groups. Radicals of strong acids are chiefly used as mobile substituents which can be split otf as anion, in particular halogen atoms, of these preferably chlorine, or also bromine or fluorine, the mobility of which is due, for example, to the bond to B-carbon atoms in negatively substituted organic radicals, to carbon atoms of nitrogen heterocycles of aromatic character which are adjacent to a tertiary ring nitrogen atom, in this case, preferably 6-membered heterocycles having at least two tertiary ring nitrogen atoms; or aromatically bound halogen atoms in oor/and p-position to one (or more) electrophilic group(s) eg. the N0 or S0 group, in particular, mainly fluorine or chlorine atoms. Additional examples of mobile substituents which can be split off as anion are: the radical of sulphuric acid in sulphated }8 hydroxyalkyl compounds, e. g. in sulphated fl-hydroxyalkyl sulphonyl and sulphamyl groups, or the radical of hydroxyaryl compounds in O-aryl urethane groups.

Dyestuffs usable according to the invention contain the substituent which can be split off as anion, for example, in the form of fi-chloroor ,B-bromo-fatty acid amide groups, in this case particularly fi-chlorocrotonic acid amide or ,B-bromopropionic acid amide groups, in the form of fluoroor chloro-nitrobenzoyl-amino groups or fiuoro or chloro-nitrobenzene sulphonylamino groups in which the fluorine or chlorine atoms are in the or/ and p-position to the nitro group(s), and preferably in the form of chloroor bromo-diazinylamino groups or chloroor bromo-triazinylamino groups, in which case particularly monochloroor dichloro-s-triazinylamino groups and, preferably, dior trichloropyrimidylamino groups. Dyestuffs having at least one and not more than two dior trihalogen pyrimidylamino groups and at least two and maximally five sulphonic acid groups are preferred in the dyeing processes according to the invention.

An advantage of the treatment according to the invention over the known processes is the elimination of an alkaline after-treatment with, for example ammonia or hexamethylenetetramine. This advantage becomes most apparent in the dyeing of wool which is sensitive to alkali, as the danger of injury to the fibers inherent in the alkaline after-treatment is avoided.

Moreover, the control of producing the desired shade more exactly is facilitated since changes in shade due to shifting of the pH of the dyeing medium from acid to alkaline and possibly back to acid are avoided.

Dyeings or prints on polyamide fibers attained according to the invention are distinguished by pure, strong and even shades and good fastness properties. In particular, they have remarkable wet fastness properties, for example fastness to water, washing, milling and perspiration, and particularly to sea water.

The following non-limitative examples illustrate the invention. Where not otherwise stated, parts and percentages are given by' weight unless stated otherwise. The relationship of parts by weight to' parts by volume is as that of grams to cubic centimeters. The temperatures are given in degrees centi grade.

Example 1 100 parts of wool are dyed in 4000 parts of a dye liquor 4 which contains the following agents: 4 parts of a dyestulf of the formula 05 part of a condensation product of 1 mol of oleic acid and 2 mols of diethanolarnine produced as described in US. Patent No. 2,089,212 and 4 parts of 80% acetic acid.

The goods are introduced into the liquor at 50, dyeing is performed for minutes at this temperature, the bath is brought to the boil within minutes and dyeing is continued at the boil for minutes.

The dyebath is then allowed to cool to about -80 whereupon parts of a solution of 30 g. per liter of a condensation product of formaldehyde with dihydroxydiphenyl sulphone and naphthalene sulphonic acids are added thereto. The production of the condensation product is described below.

This mixture is left for 15-20 minutes at about 60-80". The liquor is then cooled, the Wool is well rinsed with water, squeezed out and dried.

Valuable vivid blueish red dyeings are obtained in this manner. The dyeings are very wet fast.

The condensation product mentioned is obtained as follows:

100 parts of the sulfonating mixture, obtained by heating for several hours at -160", 520 parts of naphthalene and 560 parts of concentrated. sulphuric acid until water solubility is attained, are heated for about 1 hour at 105-110 with 100 parts of a dihydroxydiphenyl sulphone, 50 parts of water and 45 parts of formaldehyde (30% The dihydroxydiphenyl sulphone is obtained by heating 540 parts of phenol and 180 parts of 60% oleum for 3 hours at 180 and distilling off excess phenol. If, instead of the dyestuff given inthe example, the dyestuffs mentioned in column 2 of the following table are used and otherwise the procedure described is followed,

45 then wool dyeings as given in column 3 are obtained.

TABLE No. Dyestuff Shade on wool (ilHx C1 s0,rr %C-N=N\ N/ \N 1 Q-N-O H l Greenish I HO3S-NHC CCl yellow. Cl OH CH $1 0 l H XI 2 a -N=N--NH-( i d o1 Reddish I- I \N% yellow.

SOnH CH:

Cl (5 N N H? ITIH-( /C 7Cl 3 -N -=N- N Red.

SO H SO;H SOaH TAB LEContinued.

No. Dyestufi Shade on wool S 3H 0 H 11 N=N Orange.

s 0 H IIIS 0 ,--o1

CH3 S 0 3H I N on S 03H OH S 03H 1 I CN 12 N= O I Greenish S 03H yellow. =N NH I I CH 0 O N on Example 2 100 parts of nylon 6 are dyed in 4000 parts of a dye liquor which contains 1.5 parts of a dyestuff of the formula and 1 part of 80% acetic acid.

The goods are introduced at 40, dyeing is performed for 10 minutes at this temperature, the bath is brought to the boil within 30 minutes and dyeing is continued for 45 minutes at the boil.

The dyebath is then allowed to cool to about 60- 80 and then 100 parts of a solution of 30 g. per liter of the formaldehyde/dihydroxydiphenylsulphone/naphthalene sulfonic acids condensation product mentioned in paragraph 3 of Example 1 is added.

This mixture is left for -20 minutes at about 60- 80. The bath is then cooled, the nylon is well rinsed with water, squeezed out and dried.

In this way valuable greenish yellow, very wet fast dyeings are obtained.

We claim:

1. In a process for dyeing polyamide fibers which process comprises heating and thereby reacting, in an acid dyebath, said fibers with a reactive dyestuff which contains at least one mobile substituent which is split off as anion, the improvement comprising (I) adding to the dyebath which still contains the fibers, after the dye has drawn onto the latter, a condensation product of (a) a member selected from the group consisting of a naphthalene sulfonic acid and a 1,2,3,4- tetrahydronaphthalene sulfonic acid, (b) from about 0.5 to 1.5 parts by weight of a compound of the formula HOphenyleneSO phenyleneOH per part by weight of (a), and

(c) from about 0.1 to 0.2 part by weight of formaldehyde per part by weight of (a), in aqueous solution, and

(II) heating the dyebath and fibers therein for about 10 to 60 minutes at a temperature of about 50 to 100 C.

2. The improvement described in claim 1, wherein the member (a) is a naphthalene-monosulfonic acid.

3. The improvement described in claim 1, wherein the member (a) is naphthalene-Z-sulfonic acid.

4. The improvement described in claim 1, wherein the compound under (b) is 4,4'-dihydro-diphenylsulfone.

5. The improvement described in claim 1, wherein the compound under (b) enters into the condensation product at a ratio of 0.8 to 1.2 parts by weight per part by weight of (a).

6. The improvement described in claim 1, wherein the heating under step (II) is carried out for about 15 to 30 minutes.

7. The improvement described in claim 1, wherein the dyebath and fibers therein are heated in step (II) at a temperature of about 60 to C.

8. The improvement described in claim 1, wherein said reactive dyestutf contains at least two and maximally five sulfonic acid groups and at least one and not more than two dihalopyrirnidylamino groups.

9. The improvement described in claim 1, wherein said reactive dyestuff contains at least two and not more than five sulfonic acid groups and at least one and not more than two trihalopyrimidylamino groups.

10. The improvement described in claim 1, wherein said reactive dyestutf contains from one to two dihalo-striazinylamino groups and from two to five sulfonic acid groups.

11. Process according to claim 1 wherein said polyamide fibers are selected from the group consisting of nylon, silk and wool.

12. Process according to claim 1 wherein said poly amide fibers are silk.

13. Process according to claim 1 wherein said polyamide fiebrs are wool.

14. Process according to claim 1 amide fibers are nylon.

15. The improvement described in claim 1 wherein the pH of the dyestuif is adjusted to between 4 and 5.5 after the dyestulf has drawn onto the fibers but prior to the addition of the said condensation'product.

16. The improvement described in claim 1 wherein prior to dyeing the fibers in the dyebath, a condensation wherein said poly- 9 10 product of fatty acid of at least 8 carbon atoms and References Cited by the Examiner ligvgveguilillrgigsolamine is added to the dyebath as the dye- UNITED STATES PATENTS 17. The improvement described in claim 16 wherein 2,623,806 12/1952 Fuch? the condensation product of oleic acid and diethan0l- 5 3,118,723 1/ 1964 Hardmg X amine in a molar ratio of 1:2 is used as the dyeing aux- 1 NORMAN TORCHIN, Primary Examiner.

18, The improvement described in claim 16 wherein HERBERT, Assistant Examiner said dyeing auxiliary is added in an amount of about 0.5% calculated on the weight of the fibers being dyed. 10 

1. IN A PROCESS FOR DYEING POLYAMIDE FIBERS WHICH PROCESS COMPRISES HEATING AND THEREBY REACTING, IN AN ACID DYEBATH, SAID FIBERS WITH A REACTIVE DYESTUFF WHICH CONTAINS AT LEAST ONE MOBILE SUBSTITUENT WHICH IS SPLIT OFF AS ANION, THE IMPROVEMENT COMPRISING (I) ADDING TO THE DYEBATH WHICH STILL CONTANS THE FIBERS, AFTER THE DYE HAS DRAWN ONTO THE LATTER, A CONDENSATION PRODUCT OF (A) A MEMBER SELECTED FROM THE GROUP CONSISTING OF A NAPHTHALENE SULFONIC ACID AND A 1,2,3,4TETRAHYDRONAPHTHALENE SULFONIC ACID, (B) FROM ABOUT 0.5 TO 1.5 PART BY WEIGHT OF A COMPOUND OF THE FORMULA 